Sobre O CSS.

CSS:

css
body {
	margin: 0;
	padding: 0;
	font-family: Arial, sans-serif;
	background-color: #f2f2f2;
}

#game {
	position: absolute;
	top: 50px;
	left: 50px;
	width: 800px;
	height: 600px;
	background-color: #fff;
	border: 1px solid #ccc;
	box-shadow: 0px 0px 10px #ccc;
}

#menu {
	position: absolute;
	top: 50px;
	left: 50px;
	width: 300px;
	height: 50px;
	background-color: #fff;
	border: 1px solid #ccc;
	box-shadow: 0px 0px 10px #ccc;
	display: none;
}

#new-game, #load-game, #options, #credits {
	position: absolute;
	top: 5px;
	left: 5px;
	width: 100px;
	height: 30px;
	background-color: #4CAF50;
	color: #fff;
	border: none;
	border-radius: 5